如何在 C++ 中从映射中删除最后一个元素
在此,我们将看到如何从 C++ STL 映射中删除最后一个元素。映射是基于哈希表的数据类型,它具有键和值。我们可以使用 prev() 方法获取最后一个元素,并使用 erase() 函数进行删除,如下所示。
示例
#include<iostream> #include<map> using namespace std; int main() { map<string, int> my_map; my_map["first"] = 10; my_map["second"] = 20; my_map["third"] = 30; cout << "Map elements before deleting the last element:"<<endl; for (auto it = my_map.begin(); it != my_map.end(); it++) cout << it->first << " ==> " << it->second << endl; cout << "removing the last element from the map"<<endl; my_map.erase(prev(my_map.end())); cout << "Map elements after deleting the last element :"<<endl; for (auto it = my_map.begin(); it != my_map.end(); it++) cout << it->first << " ==> " << it->second << endl; }
输出
Map elements before deleting the last element: first ==> 10 second ==> 20 third ==> 30 removing the last element from the map Map elements after deleting the last element : first ==> 10 second ==> 20
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